This invention relates to a switch for actuating a plurality of vehicle functions remotely wherein the switch can distinguish an inadvertent actuation from an intended actuation.
Vehicle remote signaling devices are becoming widely utilized. Such devices, commonly known as key fobs, incorporate a number of switches for actuating various functions remotely. Examples include door unlock, door lock, trunk unlock, ignition start, etc. There are varying conflicting design criteria for these devices. On the one hand, it is desirable that the devices be small enough to be convenient for carrying. Typically, operators carry these devices in their pocket or purse, and thus it is desirable to keep the devices somewhat small.
On the other hand, as the devices become more popular, it becomes desirable to incorporate more functions into the devices. Each new function has typically required the addition of a further switch. While proposals have been made for utilizing a single switch for a mode control switch such that a single switch can provide various functions, these have not been widely accepted by users.
Thus, at present, there is a trade-off in the design of remote signaling devices with regard to the size and the number of switches which can be incorporated into the devices.
Another problem with these devices is that as more switches are incorporated into the devices inadvertent actuation of a switch becomes a more pronounced problem. These inadvertent actuations can occur when a user accidentally touches a switch when handling the device. As an example, a user carrying the device towards a car may inadvertently actuate the trunk unlock, panic alarm, or some other function which is not desirable.
In the disclosed embodiment of this invention, a remote signaling device for vehicles is provided with switches which can distinguish between inadvertent and intentional actuations. If an inadvertent actuation occurs, then the function is not actuated. That is, a control senses characteristics of the actuation, and determines whether an intended actuation has occurred. If the control determines that an intended actuation has not occurred, then no actuation will be made. On the other hand, if the characteristics indicate that the actuation is intended, then the function will be actuated.
In one disclosed embodiment of this invention, the switch incorporates a device known as a field limited capacitive switch. Such switch devices are known and utilized in appliance applications. As an example, ovens and ranges are often provided with this type of switch. In this type of switch, the switch senses the proximity of ionic material in a single direction relative to the switch. Typically, the single direction is upward and forward of the switch. If there is ionic material sensed in proximity to the switch then the inventive switch identifies the amount of material in proximity to the switch.
This type of switch provides powerful benefits to a remote signaling device. In particular, the switch senses the amount of ionic material, and provides an indication of the amount to a control. If the control identifies that the amount of ionic material is greater than that which would be indicative of an intended actuation, or if it determines the amount of material is less than that which would be indicative of an intended actuation, then no further step is taken. However, if the amount of material is within a range, then the function is actuated.
The ionic material in this instance will be the hand of a user. The use of this type switch provides additional benefit in that switches can be placed on all sides of the key fob. Thus, the switch can be placed on both the bottom and top of a key fob. Such placement would be undesirable without the ability to distinguish between inadvertent and intended actuation. As an example, switches on the bottom of a key fob might be inadvertently actuated while held in the hand of an operator. With the present invention the switches being held in the palm of a user""s hand will identify proximity of ionic material over their entire surface area. The control identifies this as being an inadvertent actuation, and will not actuate any function. As an example, the control can be utilized to only identify an intended actuation if the input is greater than the fifth percentile female finger, and less than a 95th percentile male finger. Objects outside this range would not trigger actuation. Further, objects within a purse or pocket would not trigger the key fob, since it is unlikely that any ionic material would be in proximity to the switch at such places.
As one further function, the sensor could also be structured such that the control will identify a small finger, such as a child""s, and provide limited access. As an example, the percentile size of an adult""s finger relative ot that of a child can be utilized to provide this determination. As an example, a child""s finger may be allowed to actuate a door lock function, but would not be allowed to unlock the ignition or start the vehicle.
These and other features of the present invention can be best understood from the following specification and drawings, the following which is a brief description.